diff options
Diffstat (limited to 'MdeModulePkg/Core/PiSmmCore/Dependency.c')
| -rw-r--r-- | MdeModulePkg/Core/PiSmmCore/Dependency.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/MdeModulePkg/Core/PiSmmCore/Dependency.c b/MdeModulePkg/Core/PiSmmCore/Dependency.c new file mode 100644 index 0000000000..800892dc44 --- /dev/null +++ b/MdeModulePkg/Core/PiSmmCore/Dependency.c @@ -0,0 +1,371 @@ +/** @file
+ SMM Driver Dispatcher Dependency Evaluator
+
+ This routine evaluates a dependency expression (DEPENDENCY_EXPRESSION) to determine
+ if a driver can be scheduled for execution. The criteria for
+ schedulability is that the dependency expression is satisfied.
+
+ Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License which accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "PiSmmCore.h"
+
+///
+/// EFI_DEP_REPLACE_TRUE - Used to dynamically patch the dependecy expression
+/// to save time. A EFI_DEP_PUSH is evauated one an
+/// replaced with EFI_DEP_REPLACE_TRUE. If PI spec's Vol 2
+/// Driver Execution Environment Core Interface use 0xff
+/// as new DEPEX opcode. EFI_DEP_REPLACE_TRUE should be
+/// defined to a new value that is not conflicting with PI spec.
+///
+#define EFI_DEP_REPLACE_TRUE 0xff
+
+///
+/// Define the initial size of the dependency expression evaluation stack
+///
+#define DEPEX_STACK_SIZE_INCREMENT 0x1000
+
+//
+// Global stack used to evaluate dependency expressions
+//
+BOOLEAN *mDepexEvaluationStack = NULL;
+BOOLEAN *mDepexEvaluationStackEnd = NULL;
+BOOLEAN *mDepexEvaluationStackPointer = NULL;
+
+/**
+ Grow size of the Depex stack
+
+ @retval EFI_SUCCESS Stack successfully growed.
+ @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.
+
+**/
+EFI_STATUS
+GrowDepexStack (
+ VOID
+ )
+{
+ BOOLEAN *NewStack;
+ UINTN Size;
+
+ Size = DEPEX_STACK_SIZE_INCREMENT;
+ if (mDepexEvaluationStack != NULL) {
+ Size = Size + (mDepexEvaluationStackEnd - mDepexEvaluationStack);
+ }
+
+ NewStack = AllocatePool (Size * sizeof (BOOLEAN));
+ if (NewStack == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ if (mDepexEvaluationStack != NULL) {
+ //
+ // Copy to Old Stack to the New Stack
+ //
+ CopyMem (
+ NewStack,
+ mDepexEvaluationStack,
+ (mDepexEvaluationStackEnd - mDepexEvaluationStack) * sizeof (BOOLEAN)
+ );
+
+ //
+ // Free The Old Stack
+ //
+ FreePool (mDepexEvaluationStack);
+ }
+
+ //
+ // Make the Stack pointer point to the old data in the new stack
+ //
+ mDepexEvaluationStackPointer = NewStack + (mDepexEvaluationStackPointer - mDepexEvaluationStack);
+ mDepexEvaluationStack = NewStack;
+ mDepexEvaluationStackEnd = NewStack + Size;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Push an element onto the Boolean Stack.
+
+ @param Value BOOLEAN to push.
+
+ @retval EFI_SUCCESS The value was pushed onto the stack.
+ @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.
+
+**/
+EFI_STATUS
+PushBool (
+ IN BOOLEAN Value
+ )
+{
+ EFI_STATUS Status;
+
+ //
+ // Check for a stack overflow condition
+ //
+ if (mDepexEvaluationStackPointer == mDepexEvaluationStackEnd) {
+ //
+ // Grow the stack
+ //
+ Status = GrowDepexStack ();
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+ }
+
+ //
+ // Push the item onto the stack
+ //
+ *mDepexEvaluationStackPointer = Value;
+ mDepexEvaluationStackPointer++;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Pop an element from the Boolean stack.
+
+ @param Value BOOLEAN to pop.
+
+ @retval EFI_SUCCESS The value was popped onto the stack.
+ @retval EFI_ACCESS_DENIED The pop operation underflowed the stack.
+
+**/
+EFI_STATUS
+PopBool (
+ OUT BOOLEAN *Value
+ )
+{
+ //
+ // Check for a stack underflow condition
+ //
+ if (mDepexEvaluationStackPointer == mDepexEvaluationStack) {
+ return EFI_ACCESS_DENIED;
+ }
+
+ //
+ // Pop the item off the stack
+ //
+ mDepexEvaluationStackPointer--;
+ *Value = *mDepexEvaluationStackPointer;
+ return EFI_SUCCESS;
+}
+
+/**
+ This is the POSTFIX version of the dependency evaluator. This code does
+ not need to handle Before or After, as it is not valid to call this
+ routine in this case. The SOR is just ignored and is a nop in the grammer.
+ POSTFIX means all the math is done on top of the stack.
+
+ @param DriverEntry DriverEntry element to update.
+
+ @retval TRUE If driver is ready to run.
+ @retval FALSE If driver is not ready to run or some fatal error
+ was found.
+
+**/
+BOOLEAN
+SmmIsSchedulable (
+ IN EFI_SMM_DRIVER_ENTRY *DriverEntry
+ )
+{
+ EFI_STATUS Status;
+ UINT8 *Iterator;
+ BOOLEAN Operator;
+ BOOLEAN Operator2;
+ EFI_GUID DriverGuid;
+ VOID *Interface;
+
+ Operator = FALSE;
+ Operator2 = FALSE;
+
+ if (DriverEntry->After || DriverEntry->Before) {
+ //
+ // If Before or After Depex skip as SmmInsertOnScheduledQueueWhileProcessingBeforeAndAfter ()
+ // processes them.
+ //
+ return FALSE;
+ }
+
+ if (DriverEntry->Depex == NULL) {
+ //
+ // A NULL Depex means that the SMM driver is not built correctly.
+ // All SMM drivers must have a valid depex expressiion.
+ //
+ ASSERT (FALSE);
+ return FALSE;
+ }
+
+ //
+ // Clean out memory leaks in Depex Boolean stack. Leaks are only caused by
+ // incorrectly formed DEPEX expressions
+ //
+ mDepexEvaluationStackPointer = mDepexEvaluationStack;
+
+
+ Iterator = DriverEntry->Depex;
+
+ while (TRUE) {
+ //
+ // Check to see if we are attempting to fetch dependency expression instructions
+ // past the end of the dependency expression.
+ //
+ if (((UINTN)Iterator - (UINTN)DriverEntry->Depex) >= DriverEntry->DepexSize) {
+ return FALSE;
+ }
+
+ //
+ // Look at the opcode of the dependency expression instruction.
+ //
+ switch (*Iterator) {
+ case EFI_DEP_BEFORE:
+ case EFI_DEP_AFTER:
+ //
+ // For a well-formed Dependency Expression, the code should never get here.
+ // The BEFORE and AFTER are processed prior to this routine's invocation.
+ // If the code flow arrives at this point, there was a BEFORE or AFTER
+ // that were not the first opcodes.
+ //
+ ASSERT (FALSE);
+ case EFI_DEP_SOR:
+ //
+ // These opcodes can only appear once as the first opcode. If it is found
+ // at any other location, then the dependency expression evaluates to FALSE
+ //
+ if (Iterator != DriverEntry->Depex) {
+ return FALSE;
+ }
+ //
+ // Otherwise, it is the first opcode and should be treated as a NOP.
+ //
+ break;
+
+ case EFI_DEP_PUSH:
+ //
+ // Push operator is followed by a GUID. Test to see if the GUID protocol
+ // is installed and push the boolean result on the stack.
+ //
+ CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));
+
+ Status = SmmLocateProtocol (&DriverGuid, NULL, &Interface);
+ if (EFI_ERROR (Status)) {
+ //
+ // For SMM Driver, it may depend on uefi protocols
+ //
+ Status = gBS->LocateProtocol (&DriverGuid, NULL, &Interface);
+ }
+
+ if (EFI_ERROR (Status)) {
+ Status = PushBool (FALSE);
+ } else {
+ *Iterator = EFI_DEP_REPLACE_TRUE;
+ Status = PushBool (TRUE);
+ }
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ Iterator += sizeof (EFI_GUID);
+ break;
+
+ case EFI_DEP_AND:
+ Status = PopBool (&Operator);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ Status = PopBool (&Operator2);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ Status = PushBool ((BOOLEAN)(Operator && Operator2));
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+ break;
+
+ case EFI_DEP_OR:
+ Status = PopBool (&Operator);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ Status = PopBool (&Operator2);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ Status = PushBool ((BOOLEAN)(Operator || Operator2));
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+ break;
+
+ case EFI_DEP_NOT:
+ Status = PopBool (&Operator);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ Status = PushBool ((BOOLEAN)(!Operator));
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+ break;
+
+ case EFI_DEP_TRUE:
+ Status = PushBool (TRUE);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+ break;
+
+ case EFI_DEP_FALSE:
+ Status = PushBool (FALSE);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+ break;
+
+ case EFI_DEP_END:
+ Status = PopBool (&Operator);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+ return Operator;
+
+ case EFI_DEP_REPLACE_TRUE:
+ Status = PushBool (TRUE);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ Iterator += sizeof (EFI_GUID);
+ break;
+
+ default:
+ goto Done;
+ }
+
+ //
+ // Skip over the Dependency Op Code we just processed in the switch.
+ // The math is done out of order, but it should not matter. That is
+ // we may add in the sizeof (EFI_GUID) before we account for the OP Code.
+ // This is not an issue, since we just need the correct end result. You
+ // need to be careful using Iterator in the loop as it's intermediate value
+ // may be strange.
+ //
+ Iterator++;
+ }
+
+Done:
+ return FALSE;
+}
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